This study uses five series of demographic and health surveys to answer the question: 'Is horizontal inequality in education and wealth increasing or decreasing in the 20-year interval between 1991 and 2010?'. Horizontal inequality in education attainment has been moving in waves; however, there was an invested U-shaped trend where inequality increased between 2004 and 2007 before a declining trend in recent years. Unlike the fluctuating trends of the overall horizontal inequality in education, gender inequality in educational attainment has consistently been declining over time. The same consistent decline in education inequality is observed between urban and rural areas, and between the business city of Dar es Salaam and other sub-national regions. However, Tanzanian society is becoming more unequal in wealth with rising wealth inequality between geographical zones, gender, and also between rural and urban areas. This implies that, sub-national regions in Tanzania, men and women, and rural and urban areas are disproportionally benefiting from the impressive economic growth rates that Tanzania has experienced over the past decade.